Hard Disk - Billion Gigabytes Of Storage

Hard disk is a reliable and permanent storage device,commonly referred to as a hard drive or fixed disk drive. It is a non-volatile storage device with a set of metal disk coated with magnetic material which is mounted on a central spindle with rotates at 7200rpm. A "head" which is like a phonograph arm but in a relatively fixed position that can able to reads or writes information on the tracks.Each platter in the hard disk has the same number of tracks, and a track location that cuts across all platters is called a cylinder. In order to read a specific file, the access mechanism with the head moves to the specific cylinder. The main important thing is that the information is stored simultaneously in all tracks in the cylinder and the mechanism will access data on one cylinder at a time. The main advantage of hard dish is high storage capacity, high speed operation. Today’s computers typically come with a hard disk that contains several billion gigabytes of storage.